老農民版夜神月

  二級颶風  
編號：10 L
名稱：Jerry

  基本資料  
擾動編號日期：2019 年 09 月 16 日 01 時
命名日期　　：2019 年 09 月 18 日 17 時
撤編日期　　：2019 年 09 月 27 日 01 時
登陸地點　　：無

  巔峰時期資料  
近中心最強風速 ：85 kt
海平面最低氣壓 ：976 百帕

  過去路徑圖  

  擾動編號資料  
97L INVEST 190915 1800 8.7N 40.5W ATL 25 1009


  NHC：30%  

1. A small low pressure system is producing an elongated area of
disorganized showers and thunderstorms over the central tropical
Atlantic. Slow development is anticipated during the next day or
two, but environmental conditions are forecast to become more
conducive for development by the middle of the week, and a tropical
depression is likely to form by the end of the week while the system
moves slowly west-northwestward to northwestward.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...high...80 percent.

以上資料來自：NHC、颱風論壇整理製作

老農民版夜神月

NHC展望提升至High,70%/90%

1. A well-defined small low pressure system located about 1200 miles
east of the Lesser Antilles continues to produce disorganized
showers and thunderstorms.  However, environmental conditions are
expected to be conducive for the formation of a tropical depression
during the next day or so while the system moves slowly
northwestward to west-northwestward.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...90 percent.

t02436

15Z升格10L，上望80節未封頂，移向加勒比海。

321
WTNT45 KNHC 171447
TCDAT5

Tropical Depression Ten Discussion Number   1
NWS National Hurricane Center Miami FL       AL102019
1100 AM AST Tue Sep 17 2019

Deep convection associated with the area of low pressure over the
central Atlantic has become more persistent and better organized
this morning.  Data T-numbers from both SAB and TAFB are 2.0 on the
Dvorak scale, therefore advisories are being initiated on a tropical
depression.  The initial intensity is set at 30 kt, in line with the
satellite estimates.  The depression is forecast to move over
gradually increasing sea surface temperatures within a favorable
upper-level environment.  The only negative factor for
intensification appears to be some nearby dry air, but with low
shear conditions expected, so steady strengthening is forecast
during the next several days.  The NHC forecast calls for the
depression to become a tropical storm later today, and attain
hurricane status within 72 hours. The NHC intensity forecast is in
good agreement with the SHIPS and LGEM statistical models.

Since the depression is still in the development phase, the initial
motion is a somewhat uncertain 295/10 kt.  A strong deep-layer
ridge to the north of the cyclone should steer the depression
generally west-northwestward at a faster forward speed during the
next few days.  The track guidance is in relatively good agreement
through 72 hours, and brings the cyclone near the northern Leeward
Islands in about 3 days.  By late in the period, the cyclone is
expected to reach the western periphery of the ridge, and there is
increasing spread among the guidance.  The global model ensemble
means are along the right side of the envelope while the HWRF and
UKMET are along the left side.  The NHC track lies close the
consensus aids, which is also in good agreement with the latest
ECMWF.

Interests in the northern Leeward Islands should monitor the
progress of this system.

FORECAST POSITIONS AND MAX WINDS

INIT  17/1500Z 12.9N  44.9W   30 KT  35 MPH
12H  18/0000Z 13.8N  46.1W   35 KT  40 MPH
24H  18/1200Z 14.7N  47.9W   40 KT  45 MPH
36H  19/0000Z 15.5N  50.2W   45 KT  50 MPH
48H  19/1200Z 16.3N  52.9W   55 KT  65 MPH
72H  20/1200Z 18.2N  59.2W   65 KT  75 MPH
96H  21/1200Z 20.2N  64.7W   75 KT  85 MPH
120H  22/1200Z 22.5N  69.0W   80 KT  90 MPH

$$
Forecaster Brown

老農民版夜神月

NHC18/09Z報升格10L為TS,命名Jerry

WTNT45 KNHC 180901
TCDAT5

Tropical Storm Jerry Discussion Number   4
NWS National Hurricane Center Miami FL       AL102019
500 AM AST Wed Sep 18 2019

Enhanced BD-curve infrared imagery and a 0431 UTC AMSR2 microwave
pass indicate that the cyclone has become better organized during
the pass several hours.  Although the surface center is still
situated near the northeastern edge of the convective mass, the
deep convection has expanded in the form of curve bands in the south
portion of the cyclone.  Based on the increased subjective and
objective satellite intensity estimates, and the improved microwave
presentation, the initial intensity is raised to 40 kt making the
system the tenth named storm of the season.

Even though the shear is low and the sea surface temperatures are
warm, GOES-16 sounder data and the GFS/ECMWF SHIPS intensity models
indicate that the environment surrounding the cyclone is still a
little dry and stable.  Therefore, only gradual intensification is
forecast.  The shear is forecast to increase after 24 hours or so,
to the point where it should slow, or halt development, and this is
reflected in the official forecast.  It should be noted that the
forecast still calls for the cyclone to become a hurricane as it
approaches the northern Leeward Islands.

The initial motion is estimated to be west-northwestward, or 290/11
kt, within the low to mid-tropospheric steering flow produced by a
subtropical ridge to the north of the tropical storm.  This general
motion is expected to continue during the next 3 to 4 days.
Afterward, a northwest to north-northwestward turn, influenced by a
growing weakness in the aforementioned ridge, is expected.  The NHC
track forecast is basically an update from the previous advisory and
lies in the middle of the guidance suite, and hedged toward the HCCA
multi-model consensus.


Key Messages:

1. Jerry is expected to strengthen and be a hurricane when
its moves near the northern Leeward Islands Friday, although it is
too soon to determine if there will be any direct impacts in the
islands. Interests there should ensure they have their hurricane
plan in place and monitor the progress of this system.


FORECAST POSITIONS AND MAX WINDS

INIT  18/0900Z 14.1N  47.7W   40 KT  45 MPH
12H  18/1800Z 14.8N  49.4W   45 KT  50 MPH
24H  19/0600Z 15.7N  52.0W   55 KT  65 MPH
36H  19/1800Z 16.8N  54.9W   60 KT  70 MPH
48H  20/0600Z 17.9N  57.9W   65 KT  75 MPH
72H  21/0600Z 20.2N  64.2W   65 KT  75 MPH
96H  22/0600Z 22.8N  68.6W   65 KT  75 MPH
120H  23/0600Z 25.6N  70.2W   65 KT  75 MPH

$$
Forecaster Roberts

老農民版夜神月

NHC19/15Z升格一級颶風

WTNT45 KNHC 191456
TCDAT5

Hurricane Jerry Discussion Number   9
NWS National Hurricane Center Miami FL       AL102019
1100 AM AST Thu Sep 19 2019

Satellite images indicate that the center of Jerry is on the
northwestern side of the central dense overcast near a very deep
convective burst.  An Air Force recon plane just flew through the
center and found a central pressure of 988 mb and SFMR values near
65 kt.  These data support making Jerry the 4th hurricane of the
2019 Atlantic hurricane season with initial wind speed of 65 kt.

Jerry has the potential to further strengthen today, but an
increase in northwesterly shear related to an upper-level ridge is
anticipated overnight. This change in shear will likely arrest the
development of Jerry and start a slow weakening trend sometime
tomorrow. In 3 or 4 days, Jerry could enter a more conducive
environment for strengthening, but there is a pretty large spread in
the shear forecast near the cyclone at this time, related to the
positioning of Jerry relative to the ridge. Since the environmental
uncertainty at long range is so high, little change has been made to
the previous forecast.

The initial motion is estimated to be west-northwestward, or 295/14
kt.  The track forecast has remained rather consistent during the
past several cycles, taking Jerry just north of the Leeward
Islands during the first couple of days due to seemingly reliable
steering flow from the subtropical ridge to the north. The track
is a little trickier beyond that time due to some dependence on the
strength of Jerry, with a stronger system likely moving a
bit longer toward the west-northwest, similar to the latest
ECMWF/HWRF forecast. Regardless, the cyclone should eventually turn
northward and northeastward by day 5 due to a substantial break in
the subtropical ridge.  The track forecast puts slightly greater
weight on those stronger solutions, and the official track forecast
is a little left of the various consensus aids and not too far from
the last NHC prediction.

Key Messages:

1. Although the core of Jerry is expected to pass north of
northern Leeward Islands, tropical-storm-force winds and locally
heavy rainfall are possible, and tropical storm watches are in
effect.

FORECAST POSITIONS AND MAX WINDS

INIT  19/1500Z 16.8N  54.4W   65 KT  75 MPH
12H  20/0000Z 17.5N  56.5W   75 KT  85 MPH
24H  20/1200Z 18.5N  59.3W   75 KT  85 MPH
36H  21/0000Z 19.5N  62.1W   70 KT  80 MPH
48H  21/1200Z 20.7N  64.8W   65 KT  75 MPH
72H  22/1200Z 23.5N  68.6W   60 KT  70 MPH
96H  23/1200Z 26.5N  70.0W   65 KT  75 MPH
120H  24/1200Z 30.5N  67.0W   65 KT  75 MPH

$$
Forecaster Blake

老農民版夜神月

NHC20/03Z報升C2,90節.20/09Z報維持,並預測已達巔峰
20/03Z報

WTNT45 KNHC 200246
TCDAT5

Hurricane Jerry Discussion Number  11
NWS National Hurricane Center Miami FL       AL102019
1100 PM AST Thu Sep 19 2019

The Air Force Hurricane Hunters investigating Jerry this evening
found that the hurricane has strengthened.  Based on the 700 mb
flight-level winds from the aircraft, the current intensity is
estimated to be about 90 kt.  It should be noted that this is
substantially higher than the intensity estimates provided from
satellite data, and underscores the value of aerial reconnaissance
of tropical cyclones.  An expected increase in vertical shear in a
day or so is expected to cause a weakening trend to commence in 12
to 24 hours, however, Jerry should remain a hurricane throughout the
forecast period.  This NHC intensity forecast is higher than the
previous one mainly due to the higher initial wind speed, and is
near or a little above the model consensus.

Jerry remains on track and continues to move west-northwestward, or
295/14 kt.  Over the next couple of days, the hurricane should
continue this general motion with some slowing of forward speed as
it moves along the southwestern periphery of a subtropical ridge.
Thereafter, Jerry is likely to turn to the northwest, then
north-northwest, and north as it moves through a weakness in the
ridge.  The track prediction models are in good agreement on this
scenario, and the official forecast is quite close to the previous
one.  This is also very similar to the NOAA corrected consensus
model, or HCCA, track.

Key Messages:

1. Although the core of Jerry is expected to move north of the
northern Leeward Islands, life-threatening flash floods are
possible, along with tropical-storm-force winds in some areas.


FORECAST POSITIONS AND MAX WINDS

INIT  20/0300Z 18.0N  57.2W   90 KT 105 MPH
12H  20/1200Z 18.8N  59.3W   90 KT 105 MPH
24H  21/0000Z 20.0N  62.0W   85 KT 100 MPH
36H  21/1200Z 21.2N  64.5W   75 KT  85 MPH
48H  22/0000Z 22.6N  66.4W   70 KT  80 MPH
72H  23/0000Z 25.7N  68.4W   65 KT  75 MPH
96H  24/0000Z 29.0N  67.2W   65 KT  75 MPH
120H  25/0000Z 35.0N  63.0W   65 KT  75 MPH

$$
Forecaster Pasch

20/09Z報

WTNT45 KNHC 200838
TCDAT5

Hurricane Jerry Discussion Number  12
NWS National Hurricane Center Miami FL       AL102019
500 AM AST Fri Sep 20 2019

Jerry appears to have stopped strengthening for now.  The last
reports from the Air Force Hurricane Hunters indicated that the
minimum pressure had risen slightly, and the satellite appearance
has become a little more ragged during the past several hours.
Radar images sent from the aircraft showed a well-defined inner
core, but there are no hints of an eye in geostationary satellite
images.  The initial intensity is held at 90 kt based on the earlier
aircraft data.  Both the Air Force and NOAA Hurricane Hunters will
be investigating Jerry later today, and that data should provide a
better assessment of its intensity and structure.

Jerry continues to move west-northwestward at a relatively quick
pace of 14 kt.  This motion is expected to continue for about
another 24 hours as the cyclone is steered by a subtropical ridge to
its northeast.  The ridge is expected to weaken and slide eastward
late this weekend in response to an eastward-moving trough over the
north Atlantic.  This change in the steering pattern should cause
Jerry to slow down and gradually turn to the northwest and then the
north late this weekend and early next week.  A faster north-
northeastward motion is anticipated toward the end of the forecast
period as another trough approaches the system.  The models remain
in very good agreement on the hurricane passing well to the north of
the northern Leeward Island and Puerto Rico late today and Saturday
and possibly moving near Bermuda in a little more than 4 days.
The only notable change this cycle is a slower northward motion from
days 3 to 5 to be in better agreement with the latest models.

The intensity forecast is a bit more challenging.  The global models
show a relatively favorable upper-level wind pattern over Jerry
during the next couple of days, but there is also a significant
amount of dry air around the cyclone.  Although the shear could
increase early next week, some of the models show Jerry deepening,
likely due to baroclinic effects due to the nearby trough. There is
a very large spread in the intensity guidance ranging from SHIPS and
LGEM showing little change in strength to pronounced weakening shown
by HMON during the forecast period.  The NHC intensity forecast is
between those extremes and lies a little above the consensus aids.

Key Messages:

1. Although the core of Jerry is expected to move north of the
northern Leeward Islands, heavy rainfall and flash floods are
possible there today.

FORECAST POSITIONS AND MAX WINDS

INIT  20/0900Z 18.4N  58.7W   90 KT 105 MPH
12H  20/1800Z 19.1N  60.8W   85 KT 100 MPH
24H  21/0600Z 20.4N  63.3W   80 KT  90 MPH
36H  21/1800Z 21.8N  65.4W   75 KT  85 MPH
48H  22/0600Z 23.2N  67.1W   70 KT  80 MPH
72H  23/0600Z 26.1N  68.4W   65 KT  75 MPH
96H  24/0600Z 29.4N  66.8W   65 KT  75 MPH
120H  25/0600Z 34.6N  63.0W   65 KT  75 MPH

$$
Forecaster Cangialosi